Biochemical changes associated with application of biocontrol agents on Indian mustard leaves from plants infected with Alternaria blight

Abstract

The present investigation reports the biochemical changes associated with application of biocontrol agents on Indian mustard (Brassica juncea L Cv RLM 1359) leaves from plants infected with Alternaria blight. Indian mustard seeds were treated separately with three biocontrol agents, viz. Trichoderma harzianum, Pseudomonas fluorescens and Bacillus subtilis and grown in experimental fields; followed by spraying on 30 and 60 days after sowing (DAS). The use of biocontrol agents showed enhanced growth in comparison to control, decreased disease index on the leaves as well as the pod wall of Indian mustard. These biocontrol agents enhanced the content of dry matter, total phenol, ortho-dihydroxyphenols, starch, total soluble sugars, reducing sugars, total lipids and different membrane lipids in the leaves. The total protein content decreased after treatment with biocontrol agents at 30 and 60 days after sowing. The data suggested that treatment with biocontrol agents initiated in the plants a number of biochemical changes which can be considered to be a part of plant defense response.